Liquid lubricant composition



United States Patent Ofitice 3,1 6 1,59 6 Patented Dec. 1 5, 1 964 3,161,596 LlQUll) LUBRICANT CGMPOSITIGN George M. Calhoun, Berkeley, Calif, assignor to Shell Oil Company, a corporation of Delaware No Drawing. Filed Dec. 14, 1359, Ser. No. 85%128 3 Claims. (Cl. 252-465) alkyl phosphites or phosphates, or free fatty acids and sulfur derivatives thereof such as C1048 fatty acids (oleic or stearic acids) and sulfurized unsaturated fatty acids, e.g., sulfurized oleic acid. However, these compounds when used in liquid hydrocarbons, such as lubricating oil compositions which are subjected to high temperatures and pressures break down and fail to impart their expected desired properties under extreme conditions.

It has now been discovered that liquid hydrocarbon compositions are improved with respect to stability, wear inhibition and extreme pressure properties and contribute to minimizing octane requirement increases when used in an internal combustion engine, and the like by incorporating therein a minor amount of an oil-soluble omegapolar-substituted Z-thiaalkyl phosphono-containing compound having the general formula:

XRi

XRi

wherein R is an oil-soluble hydrocarbyl group, such as an alkyl, aryl, aralkyl, alkaryl or cycloalkyl radical having at least 2 and preferably being an alkyl radical having from 6'to 18 carbon atoms, R is a C alkyl radical or hydrogen, the Rfs are the same or different groups selected from hydrogen, hydrocarbyl, or cationic groups, such as metallic or non-metallic cationic group, such as mono or polyvalent metal or amine, preferably an alkylamine, the Xs are independently chalcogen atoms having an atomic number of from 8 to 16, i.e., oxygen or sulfur, and Y is a polar radical such as halogen, XR CXXR N(R) Where the Xs and R s are the same as defined above,-With preferred polar group being -OH, COOH and Cl. Preferred compounds of the general Formula I have the following formula:

C 10-15 alkyl-S C H;- P

0 B1 (II) where Z is a hydroxyl, carboxyl or chloride group.

The omega-polar substituted 2 thiaalkyl phosphono compounds are prepared by reacting an omega-polar substituted mercaptan having at least 2 carbon atoms with a halomethylphosphono compound such as chloromethylphosphonic acid or its ester or salt derivative in a suitable solvent, such as an aqueous alcoholic solution, at reflux temperature and under inert conditions until the reaction is completed which normally may require up to about 5 days. The omega-substituted mercaptans include omegasubstituted aliphatic mercaptans such as omega-hydroxy, omega-carboxy, omega-aminoethyl, butyl, hexyl, octyl, decyl, dodccyl, octadecyl, phenyldecyl, benzyl mercaptans and the like. 7

The following examples illustrate the preparation of the additives for use in accordance with the present invention.

EXAMPLE I stoichiometric amounts of dibutyl chloromethyl phosphonate and beta-carboxy ethyl rnercaptan (HSCH CH COOH) were dispersed in an aqueous solution of ethyl alcohol and KOH and refluxed under a nitrogen atmosphere for about 24 hours. The final product was recovered by acidification and extraction with ether. It was dibutyl delta-carboxy-Z-thiabutyl phosphonate O C4H0 T/ \O C 4H9 oil-soluble and possessed good extreme pressure and antioxidant properties.

0 (no 0 o CHzCH2 s-oinr EXAMPLE II stoichiometric amounts of dibutyl chloromethyl phosphonate and beta-omega-hydroxy substituted mercaptan (HSCH CH OH) were reacted under the conditions of Example I to yield dibutyl omega-hydroxy-2-thiamethyl phosphonate 0 00411 (HO CII2CH2 SCHg \OC4H9 which possess good oil-solubility, extreme pressure and anti-oxidant properties.

EXAMPLE III Dibutyl orncga-chloro-Z-thiabutyl phosphonate was prepared by reacting dibutyl omega-hydroxy-Z-thiabutyl phosphonate with thionyl chloride in the presence of pyridine.

EXAMPLE IV Di-Z-ethylhexylamine salt of omega-hydroxy-Z-thiabuty phosphonic acid phonate was prepared according to the procedure of EX- ample I by reacting stoichiometric amounts of monobutyl chloromethylphosphonate with potassium salt of omegacarboxydecyl mercaptan.

The following additional compounds were prepared: omega hydroxyoctylmercaptomethylphosphonic acid, omega hydroxydodecylmercaptomethylphosphonic acid, omega-aminohexylmercaptomethylphosphonic acid, omega-chlorohexylmercaptomethylphosphonic acid, omegachlorobutylmercaptomethylphosphonic acid, dibutyl omega-carboxydecylmercaptomethylphosphonate, phenyl omega-carboxydecylmercaptomethyl acid phosphonate, dithiobutyl omega carboxyhexylmereaptomethylphosphonate, tcrt-octadecylamine omega-hydroxydodeeylmercaptomethylphosphonate and mixtures thereof.

The additives of this invention are novel compounds. They are oil-soluble and can be used in amounts of from about 0.1% to about 25%, preferably from about 0.5% to about 5.0% by weight.

Phosphono compounds of this invention are outstanding additives for various liquid hydrocarbon products, such as natural and synthetic hydrocarbon lubricating oils, greases, fuels (gasoline, kerosene, gas oil, burner fuel oil), asphalts, waxes, slushing oils, industrial oils, e.g., metal working and drawing oils, quenching oils, textile oils, hydraulic oils, dielectric compositions and other industrial oils. They are particularly outstanding when added in small amounts to lubricating oils and lubricating compositions to impart extreme pressure and anti-wear properties to such materials. Also, these additives are useful additives for gasoline, fuel oils, and other light oil products.

Lubricating oils useful for the preparation of compositions of this invention can be one or more of a variety of synthetic oils or natural hydrocarbon oils having a viscosity range of from 50 SUS at 100 F. to 250 SUS at 210 F. (SAE viscosity number ranging from SAE W to SAE 90). The natural hydrocarbon oils can be obtained from paraifinic naphthenic, asphaltic or mixed base crudes, and/or mixtures thereof. Synthetic oils include polymerized olefins, alkylated aromatics, isomerized waxes, copolymers of alkylene glycols and alkylene oxides (Ucon fluids) which are described in US. Patents 2,425,755, 2,425,845 and 2,774,733 such as Ucon 50HB170, Ucon 50HB660 or Ucon LB SSOX and which are copolymers of ethylene and 1,2-propylene oxides, the mono and diols, as well as their ester derivatives; organic esters of aliphatic dibasic acids such as di-Z-ethylhexyl sebacate or di-Z-ethylhexyl adipate and the like. The hydrocarbon oils may be blended with fixed oils such as castor oil, lard oil and the like and/or snythetic oils as mentioned or silicone polymers and the like. Two typical oils A and B are parafiinic and naphthenic in character, respectively, having the following properties:

(SAE 10W) (SAE 30) Pour point, F 10 5 Flash, F 390 415 Viscosity, SUS at 210 44 58 "iseosity Index 90 60 Other suitable oils are the 1010 and 1065 grade gas turbine lube oils represented by the following:

The following compositions are illustrative of the invention, the percentages being by weight, of the indicated additive or additives with the remainder being essentially the base.

4 Composition A:

Example I additive 2%. 1010 Mineral oil Essentially balance. Composition B:

Example II additive 2%. 1010 Mineral oil Essentially balance. Composition C:

Example III additive 2%. 1010 Mineral oil Essentially balance. Composition D:

Example IV additive 2%. 1010 Mineral oil Essentially balance. Composition E:

Example II additive 1%. SAE 30 Mineral oil Essentially balance. Composition F:

Example I additive 2%. SAE Mineral oil Essentially balance. Composition G:

Example I additive 2%. Laurie acid 2%. SAE 90 Mineral oil Essentially balance. Composition I-I:

Example I additive 5%. Ucon 501-13660 (polyethylenepropylene glycol having an SUS viscosity at F. of 660) Essentially balance. Composition I:

Example I additive 2%. Di-Z-ethylhexyl sebacate Essentially balance. Composition J:

Example I additive 1%. Leaded gasoline (3 cc. of

TEL) Essentially balance. Composition K:

Example I additive 0.1%. Fuel Oil (No. 2) Essentially balance.

Compositions of this invention were evaluated for their extreme pressure properties in the 4-Ball Wear Machine described in Engineering Vol. 136, July 13, 1933.

Table I 4-BALL WEAR TEST [1800 r.p.m., 10 sec., steel on steel, ambient temp] Composition: Initial seizure load, kg.

Mineral oil (1010) 40-50 Composition A 158-178 Composition B 158-178 Composition C 158-178 The phosphono compounds of this invention are useful also for providing superior load-carrying properties for lubricating oils which contain minor amounts of other agents, such as silicone anti-foaming agents, alkylphenol anti-oxidants, polyacrylate ester viscosity-index improvers, long chain fatty acids such as lauric and oleic acids, oiliness agents and the like.

We claim as our invention:

1. A lubricating oil composition comprising a major amount of a lubricating oil and a minor amount, sufiicient to impart extreme pressure properties to organic liquid of an oil-soluble alkylmercaptomethylphosphono compound having the general formula wherein R is an oil-soluble C alkyl radical, the R s are selected independently from the group consisting of hydrogen and C alkyl radical, and mixtures thereof, R is selected from the group consisting of hydrogen and a C alkyl radical, X is oxygen, and Y is a polar radical selected from the group consisting of OH and -COOH radicals.

2. A mineral lubricating oil composition comprising a major amount of mineral lubricating oil and from about 0.5% to about 5% of an ester of omega-hydroxy C alkylrnercaptomethylphosphonic acid and an alkanol having from 1 to 4 carbon atoms.

3. A mineral lubricating oil composition comprising a major amount of mineral lubricating oil and from about 0.5% to about 5% of dibutyl omega-hydroxybutylmercaptomethylphosphonate.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF A LUBRICATING OIL AND A MINOR AMOUNT, SUFFICIENT TO IMPART EXTREME PRESSURE PROPERTIES TO ORGANIC LIQUID OF AN OIL-SOLUBLE ALKYLMERCAPTOMETHYLPHOSPHONO COMPOUND HAVING THE GENERAL FORMULA 